1. Field of the Invention
The present invention relates to a medical system for monitoring and localization of electrode leads in the heart.
Generally the present invention is applicable to obtain information about hemodynamic heart activity, e.g. related to heart wall movements, heart wall thickening or valve plane movement. This obtained information is then used to improve the setting of an implantable heart stimulator.
The present invention is in particular applicable to identify optimal settings of AV- and/or VV-delays in an implantable heart stimulator, and to identify optimal electrode positions within the heart and in the coronary heart vessels. The invention may be used both during implantation procedures and at follow-up procedures.
2. Description of the Prior Art
AV- and VV-delay are important hemodynamic parameters that need to be individually set for every patient and electrode position. The optimal settings of AV- and VV-delay need feedback from data disclosing the hemodynamic status at different AV/VV-delay settings. This can be performed by measuring the blood flow in the heart with e.g. ultrasound equipment. However, such equipment is normally not available during implantation of pacemakers and implantable cardioverters/defibrillators (ICDs).
In the mapping system of Endocardial Solutions three electric fields are created in the thorax of a patient by applying alternating currents between pairs of cutaneous electrode patches. The patches are arranged to let currents through the patient to be almost perpendicular to each other. The currents are time multiplexed in order to obtain only one electric field at a time. A catheter, provided with sensing electrodes, and inserted into the thorax region, e.g. inside the heart, will experience a voltage which will depend upon the projection of the electrode on the axis being parallel to the electric field. The collected information from the catheter is used to track or navigate the movement of the electrodes and to construct a three-dimensional model of the heart chambers.